Detecting RPM and rotation direction of rotary drive, e.g. window lifter of motor vehicle - using signal generating or altering element connected to rotary drive and supplying detecting sensor and electronic evaluation unit

摘要

A rotation of the signal generating or altering element produces a cyclic, direction of rotation coded signal. This signal is detected by the sensor (3) and is supplied to the electronic evaluation unit. The coded signal has at least one extreme value. Different rising or falling signal amplitudes occur when approaching different sides of the extreme value, and/or related to a 360 deg. cycle, the extreme values are distributed non-uniformly with at least one spacing, which is not equal to the ratio of 360 deg. to the number of the extreme values. USE/ADVANTAGE - Motor vehicle window lifters or sliding roofs. Gives high resolution of rotational speed and direction of rotation with small prodn. cost.